The present invention relates to a thermoplastic resin composition having high electrical conductivity, excellent thin-wall moldability, good appearance and high flame retardancy, and to a molding material and a molded article that are made from the thermoplastic resin composition.
It has conventionally been known that a thermoplastic resin composition having a desired electrical conductivity and a molded article thereof are obtained by compounding an electrically conductive fiber (or an electrically conductive filler) with a resin.
Thermoplastic resin compositions obtained by compounding electrically conductive fibers (or electrically conductive fillers) and molded articles thereof as mentioned above typically exhibit volume resistivity above 2.5 xcexa9xc2x7cm, and are rarely applied to uses where a volume resistivity less than that value is preferable, for example, electromagnetic wave shield materials and the like. In cases where a volume resistivity of less than 2.5 xcexa9xc2x7cm is required, simple increases in the amount of an electrically conductive fiber (or a electrically conductive filler), or a combined use of an electrically conductive fiber and another electrically conductive filler and the like, have been attempted.
An attempt to raise the electrical conductivity by increasing the amount of the electrically conductive fiber (or electrically conductive filler) almost always results in unreasonable increases in the costs and the specific gravities of the thermoplastic resin composition and molded articles thereof, and gives rise to problems of, for example, considerable reductions in the impact strength and the moldability (flowability during a molding process or the like) and, moreover, impairment of the appearance of molded articles. With regard to the aforementioned problem of viscosity increase of the composition, an art of physically compounding large amounts of various carbon blacks is proposed, for example, in JP-A-7330987.
An art of using a combination of an electrically conductive fiber and an electrically conductive filter (carbon black, in blow proposals) is proposed, for example, in JP-A-9-87417 and JP-A-8-269228 (U.S. Pat. No. 5,750,616). However, none of these proposals satisfies the requirements of high electrical conductivity and thin-wall moldability altogether.
In view of the aforementioned background of the conventional arts, the invention is intended to provide a thermoplastic resin composition having high electrical conductivity, excellent thin-wall moldability, good appearance, and high flame retardancy, and a molding material and a molded article thereof.
In order to achieve the aforementioned object, the invention adopts the following means. That is, the invention relates to a thermoplastic resin composition which is capable of providing a molded article whose flame retardancy with a thickness of 1.6 mm ({fraction (1/16)} inch) in accordance with an UL 94 standard is V-0 or better and which comprises a component [A], a component [B] and a component [C] mentioned below, wherein the component [B] satisfies following conditions (B1) and/or (B2):
[A]: an electrically conductive fiber
[B]: a carbon powder
[C]: a thermoplastic resin
(B1): Raman scattering intensity ratio I2/I1 is 0.55-0.8
(B2): Raman scattering intensity ratio I2/I3 is 0.54-0.8
where
I1: local maximum value of Raman scattering intensity appearing near a Raman shift of 1360 cmxe2x88x921 
I2: local minimum value of the Raman scattering intensity appearing near a Raman shift of 1480 cmxe2x88x921 
I3: local maximum value of the Raman scattering intensity appearing near a Raman shift of 1600 cmxe2x88x921 
The molding material and the molded article of the invention is characterized by processing or molding a thermoplastic resin composition as described above.